What is the atomic mass of an element? What is the atomic number of an element? How is the periodic table arranged? How did Mendeleev arrange his PT? The total number of protons and neutrons found in the elements nucleus. The total number of protons found in an element. By increasing atomic number. He arranged the element by similar properties and then by their atomic mass. Where are metals found on the Periodic table? Why is hydrogen not in group 1 of modern Periodic table? Which subatomic particles are found in an atom? What is the location of the subatomic particles in an atom? All metals are found on the left of the dividing line, which starts at group 3. Hydrogen is a gas and group 1 are all metals. Electrons, protons and neutrons Elements are found on the shells, whereas protons and neutrons are found in the centre nucleus.

Can hold up to this number of electrons What are the charges of the sub-atomic particles. What is the order of filling the electron shells? What was Rutherford's famous experiment? Rutherford's fired a beam of alpha particles, onto a sheet of very thin gold foil. Some of the alpha particles were reflected; meaning that the atom had a concentrated centre of positive charge and of relatively large mass. The alpha particles had either hit the positive centre directly or passed by it close enough to be affected by its positive charge. Since many other particles passed through the gold foil, the positive centre would have to be a relatively small size compared to the rest of the atom - meaning that the atom is mostly open space. Particle Charge Mass Proton +1 1 Neutron Electron -1 1 / 2000 Shell Can hold up to this number of electrons 1 2 8 3 4 What is the relationship between the number of protons & electrons What do groups in the periodic table show? What do periods in the periodic table show? There are two isotopes of Chlorine: 75% is 35Cl17 and 25% is 37Cl17. Calculate the relative atomic mass of copper. Give your answer to one decimal place. Periods go across the periodic table. Elements in the same period, have the same number of shells. Groups go down the periodic table. Elements in the same group have similar properties and the same number of electrons on their outer shell. (75x35)+(25x37) = 100 (2625) + (925) = 35.5% They are both the same. The No of protons is equal to the No of electrons.

How many more protons does Zn have than Ca? What charge does a group 1 element have? What charge does a group 2 element have? What charge does a group 3 element have? +1 charge. Elements in group 1 will give away their outer 1 electron, in order to become stable. +2 charge. Elements in group 2 will give away their outer 2 electrons, in order to become stable. +3 charge. Elements in group 3 will give away their outer 3 electrons, in order to become stable. Ca atomic No = 20 Zn atomic No = 30 Ans = Zn has 10 more protons. What charge does a group 5 element have? What charge does a group 6 element have? What charge does a group 7 element have? What charge does a group 8 element have? -3 charge. Elements in group 5 need 3 more electrons to become stable. -2 charge. Elements in group 6 need 2 more electrons to become stable. -1 charge. Elements in group 7 need 1 more electron to become stable. No charge. It has a full outer shell of electrons and is inert (stable).

The No of neutrons and protons in an element. There are two isotopes of Chlorine: 75% is 35Cl17 and 25% is 37Cl17. Calculate the relative atomic mass of copper. Give your answer to one decimal place. What is an isotope? What is Ar? What is the relative atomic mass of thallium which is made up from 30% thallium-203 . All the other atoms thallium-205. Calculate the relative Ar of thalium. An element with the same amount of electrons and protons and different numbers of neutrons. Atomic mass. The No of neutrons and protons in an element. (30 x 203)+(70 x 205) = 100 (6090) + (14350) = 204.4% (75x35)+(25x37) = 100 (2625) + (925) = 35.5% What is the connection between the number of outer electrons and the position of an element in the PT? What is it that moves in metals, which allows them to conduct electricity? An atom of element E has atomic number 10 and mass number 22. How many electrons does this atom contain? What is the electronic configuration of an atom? This refers to the atomic no and how many electrons are on each shell of the element. Eg: C: 6 2,4 Mg: 12. 2,8,2 Cl: 17. 2,8,7 Ca: 20. 2,8,8,2 The electrons can move. These moving electrons are called delocalised. Elements group No, is the same as the No of electrons on its outer shell. Eg: Mg, group 2, 2 electrons on outer shell. Atomic No always refers to the No of electrons and protons. Answer is 10